This invention relates to laser nozzles, optical cavity walls, and combustion manifolds. Two patents which show nozzle assemblies having individual laser nozzle members having spaced portions forming a plurality of nozzles extending across a gas manifold, including an optical cavity, are U.S. Pat. Nos. 3,602,432 and 3,819,321. U.S. Pat. No. 3,819,321 also shows an elongated injector head and cooling means. An entire laser system with flow from a combustor through a plurality of nozzles into a lasing region with reflecting walls is shown in U.S. Pat. No. 3,665,336. Another type of laser nozzle and optical cavity wall construction is shown in Application Ser. No. 794,168, now U.S. Pat. No. 4,126,271. It is noted that in the laser nozzle constructions above, the combustion distribution manifold is located behind the spaced portions of the laser nozzle members, or wafers, with flow passing through said spaced members, or wafers, from the back to the front.